<template>
  <div>
    <input type="text" v-model="message">
    {{message}}
    <button v-on:click="handleClick">click</button>
  </div>
</template>

<script>
export default {
  data() {
    return {
      message: 'hello'
    }
  },

  methods: {
    handleClick() {
      this.message = 'world'
    }
  }
}
</script>